diff --git a/build.py b/build.py
index 0c4eb986..4d350315 100755
--- a/build.py
+++ b/build.py
@@ -1455,7 +1455,7 @@ def cmd_build_wx(options, args):
                 build_options.append("--osx_cocoa")
 
             if options.mac_arch:
-            build_options.append("--mac_universal_binary=%s" % options.mac_arch)
+                build_options.append("--mac_universal_binary=%s" % options.mac_arch)
             else:
                 build_options.append("--mac_universal_binary=default")